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Field   Columbian    Museum 

Publication  53. 

Geological  Series.  Vol.  I,   No.  8. 


) 


OBSERVATIONS  ON  INDIANA 

CAVES. 


BY 


Oliver  Cummings  Farrington,   Ph.D., 
Curator,   Department  of  Geology. 


Chicago,   U.  S.  A. 
February,    1901. 


TABLE  OF  CONTENTS. 


Page 
Observations  on  Indiana  Caves,     -  -  -  -  -      247 

Wyandotte  Cave,         ...  ...  247 

Marengo  Cave,       ....  ...      256 

Shiloh  Cave,      -  -  -  -  -  262 

Coan's  Cave,  -  -  -  -  ...  .  .      26\ 


OBSERVATIONS  ON  INDIANA  CAVES. 


A  visit  of  the  writer  to  several  caves  in  Indiana  during  the 
months  of  August  and  September,  1900,  afforded  an  opportunity  for 
a  number  of  observations  which  seem  to  be  new  or  confirmatory  of 
observations  previously  published  by  others.  The  caves  visited 
were  Wyandotte  Cave,  Crawford  County;  Marengo  Cave,  Crawford 
County;  Shiloh  Cave,  Lawrence  County;  and  Coan's  Cave,  Monroe 
County,  all  in  the  State  of  Indiana.  Detailed  descriptions  of  all 
these  caves  have  been  given  in  several  reports  of  the  Geological  Sur- 
vey of  Indiana,  the  latest  and  most  complete  being  in  the  twenty-first 
annual  report,  189b,  by  W.  S.  Blatchley.  There  is  also  given  in  that 
report  a  bibliography  of  the  caves  and  their  fauna. 


WYANDOTTE  CAVE. 


Circular  or  Dome-shaped  Halls. — The  hall  known  as  "  Helen's 
Dome"  has  to  a  marked  degree  the  form  of  a  hollow  cylinder  standing 
vertically.  "  Rothrock's  Cathedral  "  has  the  form  of  a  huge  dome 
roofing  a  short  cylinder,  the  center  of  the  dome  being  in  turn  cut  by 
a  cylinder  rising  above  it.  The  "Senate  Chamber"  has  a  similar 
form  except  that  its  shape  is  elliptical  rather  than  circular.  "Odd 
Fellows'  Hall,"  "  Milroy's  Temple,"  the  "Hall  of  Representatives," 
and  others  are  likewise  dome-shaped.  The  hall  known  as  "  The 
Rotunda"  in  Mammoth  Cave  has  also  the  form  of  a  dome  roofing  a 
short  cylinder.  The  dimensions  of  some  of  the  halls  as  given  by 
Blatchley*  are  as  follows:  Helen's  Dome,  80  feet  high  and  20  feet 
in  diameter;  Rothrock's  Cathedral,  185  feet  high  and  200  feet  in 
diameter;  the  Senate  Chamber,  bo  feet  high  with  elliptical  axes  144  feet 
and  5b  feet  in  length.  The  circular  or  elliptical  contour  of  the  walls 
of  these  halls  and  the  persistence  with  which  it  is  maintained  through- 
out successive  downfalls  of  rock  is  remarkable  and  indicates  that 
some  cause  additional   to   ordinary  water  erosion   must    be  sought. 

*Op.  cit. 

247 


248  Field  Columbian  Museum — Geology,  Vol.  i. 

Water  flowing  down  vertical  joint  planes  usually  produces  pits  with 
walls  of  angular  contour,  of  which  the  "Bottomless  Pit"  in  Mam- 
moth Cave  may  serve  as  a  type.  It  is  possible  that  the  circular 
contours  may  arise  from  a  solvent  action  added  in  an  unusual 
degree  to  the  erosive  action  of  water.  By  this  means  the  solid 
angles  of  the  limestone  blocks  formed  by  the  junction  of  several  ver- 
tical with  one  horizontal  joint  plane  might  be  dissolved  away  until  a 
dome-shaped  cavity  was  formed,  or  the  form  may  be  due  to  a 
concretionary  structure  of  the  limestone  like  that  recently  noted  in 
Idaho.*  The  consecutive  removal  of  the  centers  of  successive  domes 
would  cause  each  to  fall  in  turn,  maintaining  the  dome-like  shape. 
Stream  erosion  on  the  floor  of  such  halls  may  remove  this  rocky 
debris  as  fast  as  it  falls  as  has  been  the  case  at  Helen's  Dome,  or  the 
rise  of  the  conical  pile  of  rocky  debris  (such  as  that  known  as 
"Monument  Mountain"  in  Rothrock's  Cathedral),  may  nearly  keep 
pace  with  the  fall  of  the  domes  above.  It  is  evident  that  if  this 
process  of  caving  in  is  continued  until  the  surface  is  reached, 
"cistern-like  pits  leading  down  into  the  bowels  of  the  earth"  will 
be  seen  from  above.  Such  is  the  description  given  by  W.  H.Holmest 
of  the  cenotes  or  sacred  wells  seen  in  Yucatan,  some  of  which  are  so 
round  and  even-walled  as  to  be  taken  for  works  of  art.  They  are 
often,  Holmes  states,  100  feet  or  more  in  depth  and  200  or  300  feet 
in  diameter.  It  seems  evident  from  what  has  been  stated  above  that 
human  agencies  need  not  be  appealed  to  for  the  formation  of  such  wells. 

Fissure  Systems. — Systems  of  fissures  forming  rectangles  or 
parallelograms  closely  resembling  those  produced  byDaubr£e's  well- 
known  experiment  illustrating  the  formation  of  joints  by  torsion  are 
to  be  seen  at  many  places  along  the  roof  of  the  cave.  As  an  exhibi- 
tion of  jointed  structure  on  a  horizontal  plane  they  are  very  satis- 
factory. Often  a  secondary  system  of  fissures  appears  in  conjunction* 
with  the  primary  one.  In  many  places,  such  as  the  "Pillared  Pal- 
ace," the  formation  of  stalactites  and  stalagmites  has  taken  place 
along  the  lines  of  the  joint  planes.  The  stalactites  and  stalagmites 
extend,  therefore,  in  straight  lines  in  most  cases  directly  beneath  the 
crevice  made  by  the  joint  plane. 

Distribution  of  Bats. — Bats  were  found  in  all  parts  of  the  cave 
which  I  entered,  even  in  the  so-called  "Unexplored  Regions,"  the 
entrance  to  which  is  a  passage  averaging  about  one  foot  in  height  for 
a  distance  of  60  feet.  If  the  bats  were  especially  numerous  any- 
where, it  was  in  the  hall  known  as  the    "Senate  Chamber,"   which, 

*A  curious  mineral  formation  in  Idaho  Engineering  and  Mining  Journal,  March  2, 1901. 
tField  Columbian  Museum  Publication  8,  p.  19. 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  249 

according  to  Blatchley's  measurements,  is  one  and  one-sixth  miles 
from  the  entrance  to  the  cave.  I  may  also  remark  that  I  noticed  a 
similar  wideness  of  distribution  of  the  bats  in  Coan's  Cave,  though 
that  is  only  one-eighth  of  a  mile  in  length.  These  observations 
seem  to  contradict  the  statement  of  Mr.  William  H.  Hess,*  that  "bats 
as  a  rule  go  but  a  short  distance  from  the  entrance,"  and  throw 
doubt  on  any  theory  of  the  origin  of'  nitrates  in  cave  earths  which 
rests  on  the  assumption  that  bats  do  not  inhabit  the  mora  remote 
portions  of  caves. 

Vermiform  Stalactites. — The  vermiform  stalactites  which  are  to 
be  seen  in  many  places  in  this  cave  have  attracted  the  attention  of 
many  observers  and  brought  forth  many  theories  as  to  their  origin. 
These  theories  are  admirably  summed  up  and  the  subject  ably 
treated  in  the  paper  by  Merrill  "  On  the  formation  of  stalactites  and 
gypsum  incrustations  in  caves,  "f  My  observations  lead  me  substan- 
tially to  agree  with  Merrill's  conclusion  that  the,  vermiform  character 
of  stalactites  of  this  cave  is  due  to  the  fact  that  the  drops  of  water 
making  them  have  been  guided  to  other  positions  than  those  dictated 
by  gravity  by  the  directions  assumed  by  spicules  of  calcite  in  crystal- 
lizing. It  appears  to  me,  however,  that  the  carbonate  of  lime  pro- 
ducing this  effect  must  be  in  a  condition  differing  somewhat  from  the 
ordinary  pulverulent  form  in  which  it  appears  at  the  end  of  the 
usual  stalactite  tube,  or  in  other  words,  that  some  additional  condi- 
tions must  be  appealed  to  in  order  to  lead  to  the  formation  of  stalac- 
tites of  this  sort. 

The  resemblance  of  the  stalactites  to  the  well-known  forms  of 
aragonite  denominated  flos  ferri  is  quite  striking,  and  perhaps  of  some 
significance.  Senft^  reached  the  conclusion  that  the  flos  ferri  forms 
of  aragonite  were  produced  from  very  dilute  solutions  of  carbonate  of 
lime,  which,  owing  to  protection  from  changes  of  air  and  tempera- 
ture, evaporated  very  slowly.  Calling  attention  to  the  form  of 
the  spicules  of  aragonite  he  deduced  much  the  same  theory  for*  the 
origin  of  the  flos  ferri  forms  as  that  suggested  by  Merrill  for  the 
Wyandotte  Cave  vermiform  stalactites.  It  is  characteristic  of  ara- 
gonite, however,  to  crystallize  in  slender  needles,  but  not  so  of  cal- 
cite. Tests  which  I  have  made  of  the  specific  gravity  of  the  sub- 
stance of  the  Wyandotte  vermiform  stalactites  indicates   that  it  is,  as 


♦Journal  of  Geology,  Vol.  8,  No.  2. 

tProc.  U.  S.  Nat.  Mus.,  Vol.  XVII,  pp.  77-81. 

JDie  Wanderungen  und  Wandelungen  des  kohlensaures  Kalkes,  Zeitschrift  der  Deutsche 
Geologische  Gesellachaft,  Vol.  XIII,  p.  269. 


250 


Field  Columbian  Museum — Geology,  Vol.  i. 


originally  regarded  by  Merrill,  calcite.  The  exact  stages  of  the  proc- 
ess by  which  vermiform  stalactites  of  calcite  would  be  produced 
seem  to  me,  therefore,  less  evident  than  are  those  by  which  such 
stalactites  of  aragonite  are  formed.  Yet,  until  we  have  better  knowl- 
edge it  may  be   a  reasonable   hypothesis  to  suppose  that  the   same 


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Fig.  i— Deposits  produced  by  capillary  attraction,  on  a  stalactite,  a  glass  rod  and  a  glass  tube. 

conditions  which  produce  such  forms  in  aragonite  (supposing  Senft 
to  have  correctly  judged  those  conditions)  viz.:  deposition  from 
dilute  solutions  in  sheltered  situations,  may  be  regarded  as  those 
which  would  produce  similar  forms  of  calcite.  Why,  however,  ara- 
gonite should  be  produced  in  one  case  and  calcite  in  the  other,  I  can- 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  25r 


not  say,  while  further  it  may  be  noted  that  Foote's*  experiments  led 
him  to  conclude  that  rapidity  of  crystallization  causes  the  formation 
of  aragonite  rather  than  the  slow  crystallization  which  Senft  has 
postulated. 

Deposits  Produced  by  Capillary  Attraction. — The  force  of  capil- 
lary attraction  cited  by  Merrill  as  producing  the  vermiform  stalac- 
tites is  probably  instrumental  in  modifying  the  forms  of  stalactites  in 
general  in  a  way  to  which  attention  does  not  seem  to  have  been 
called  before.  In  fact,  it  is  probable  that  deposition  from  this  cause 
takes  place  on  a  much  larger  scale  than  has  hitherto  been  supposed. 
The  nature  of  such  deposits  can  be  instructively  determined  experi- 
mentally. As  deposition  of  carbonate  of  lime  from  solutions  would 
take  place  too  slowly  for  convenient  study,  I  have  used  solutions  of 
salt  for  this  purpose. 

Fig.  1  shows  a  deposit  of  salt  formed 
by  capillary  attraction  on  a  slender 
stalactite,  a  glass  rod  and  a  glass  tube 
respectively.  These  deposits  were  ob- 
tained by  supporting  the  several  objects 
on  end  in  a  solution  of  salt  to  a  depth  of 
about  one-fourth  of  an  inch  (6  mm.)  for 
a  week.  The  deposit  on  the  stalactite, 
it  will  be  noted,  gathered  about  numer- 
ous centers  giving  a  stippled  appear- 
ance like  that  often  seen  on  stalactites 
and  illustrated  by  the  figure  of  the  stalac- 
tite shown  in  Fig.  2.  This  is  in  accord- 
ance with  the  well-known  tendency  of 
crystals  to  form  secondary  and  tertiary 
branches.  It  is  to  be  noted  so  far  as  the 
deposit  on  the  glass  tube  is  concerned 
that  none  formed  inside  the  tube. 
Hence  the  stopping  up  of  stalactite 
tubes  cannot  be  ascribed  to  this  cause. 
Attention  may  also  be  called  to  the  large 
amount  of  deposit  both  on  the  tube  and 
the  rod,  as  indicating  how  considera- 
ble a  deposit  on  stalactites  may  result 
from  capillary  attraction.  In  Nature  it 
is  to  be  supposed  that  the  capillary 
currents     producing     such     deposition 


Fig.   2— Stalactite. 


Marengo     Cave. 
showine  form  probably  influenced 
by  capillary  deposit. 
%  nat.  size.    (Mus.  No.  G.  963.) 


♦Abstract  in  Am.  Jour.  Sci.,  Vol.  160.  p.  392. 


252 


Field  Columbian  Museum — Geology,  Vol.  i. 


would  take  their  origin  from  the  larger  current  trickling  down 
the  side  of  the  stalactite  and  from  the  drop  of  water  at  the 
end.  That  currents  rise  from  the  drop  of  water  at  the  end  of  a  stalac- 
tite may  be  proved  by  the  clumsy  and  not-recommended-often-to-be- 
tried  experiment  of  holding  a  lighted  candle  for  a  moment  close 
under  the  drop.  The  particles  of  soot  thus  left  in  the  water  will  be 
seen  to  whirl  about  for  a  long  time,  much  longer  than  any  convection 
currents  produced  by  the  heat  of  the  candle  would  account  for. 
This  motion  continued  in  one  stalactite  which  I  watched  for  a  period 
of  five  minutes,  and  it,  may  be,  is  still  kept  up.  The  deposit  formed 
under  the  conditions  of  the  above  experiment  with  salt  may  be  con- 
sidered illustrative  of  one  produced  by  rapid  evaporation  from  a  con- 
centrated solution.  The  subject  evidently  admits  of  much  further 
treatment  experimentally  by  way  of  determining  what  variations,  if 
any,  would  be  produced  in  the  nature  and  amount  of  the  deposit  by 
employing  solutions  of  different  strengths,  by  varying  if  possible  the 
rate  of  evaporation  and  by  the  use  of  different  salts. 

The  "  Pillar  of  the  Constitution." — Fig.  3.  The  shape  and 
size  of  this  huge  stalagmite  have  often  been  described.  It  is  located 
in  the  hall  known    as  the    "  Senate   Chamber,"  which   is   accurately 


Fig  3— The  "Pillar  of  the  Constitution,"  Wyandotte  Cave. 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  253 

described  by  Collett*  as  "  a  vast  elliptical  amphitheatre  *  *  * 
The  sides  are  built  up  with  massive  ledges  of  limestone,  thinning 
and  converging  upward  into  a  monster  dome  with  a  flat  elliptical 
crown  50x20  feet  in  diameter.  The  center  of  this  vast  room  is  piled 
up  with  a  great  mass  of  rocky  debris  fallen  from  the  immense  cavity 
above."  Blatchleyt  gives  the  exact  measurements  of  the  hall,  so  far 
as  its  length  and  breadth  are  concerned,  as  144  feet  and  56  feet 
respectively.  He  gives  further  the  following  graphic  description  of 
the  Pillar:  '*  The  mass  of  fallen  rock  in  the  center,  known  as  'Capi- 
tol Hill,'  is  about  32  feet  in  height,  and  is  crowned  to  a  depth  of 
several  feet  with  an  immense  mass  of  stalagmitic  material.  From 
the  center  of  this  mass  rises  from  the  top  of  the  hill  the  grandest 
natural  wonder  in  Wyandotte  Cave — the  great  fluted  column  of  satin 
spar  or  crystalline  carbonate  of  lime  known  as  the  '  Pillar  of  the 
Constitution.'  Perfectly  cylindrical,  71  feet  in  circumference,  and 
extending  from  the  crest  of  the  hill  to  the  ceiling  above,  this  enorm- 
ous column  exceeds  in  magnitude  any  similar  formation  in  any  known 
cave  on  earth."  No  statement  of  the  height  of  the  Pillar  is  given  by 
this  author.  Collett  states  that  the  Pillar  is  about  35  feet  high,  and 
Mr.  H.  A.  Rothrock,  the  present  manager  of  the  cave,  informs  me 
that  this  is  undoubtedly  correct,  so  far  as  the  southern  side  of  the 
Pillar  is  concerned.  Owing  to  the  fact  that  the  stalagmite  is  situated 
a  little  to  one  side  of  the  apex  of  the  cone  of  debris,  the  deposit  has 
formed  about  ten  feet  farther  down  on  the  southern  side  than  on  the 
northern.  On  the  northern  side,  therefore,  the  height  is  about  25 
feet.  The  mean  of  these,  or  30  feet,  may  be  taken  as  the  height 
above  the  debris  as  a  wb^ole.  The  intimate  structure  of  the  mass  as 
shown  by  examining  fragments  taken  from  the  pit  artificially  exca- 
vated at  its  base  is  distinctly  banded  or  onyx-like.  The  individual 
bands  are  so  narrow  as  to  be  scarcely  distinguishable  with  the  naked 
eye,  but  these  are  grouped  into  series  of  larger  bands,  0.5  mm.  to 
5  mm.  in  thickness,  which  differ  in  color  or  in  structure  so  as  to  be 
plainly  distinguished  from  one  another.  A  secondary  fibrous  struc- 
ture in  which  the  fibres  are  at  right  angles  to  the  plane  of  deposition 
has  been  developed  through  most  of  the  bands.  The  latter  lie  for 
the  most  .part  nearly  horizontal,  but  occasionally  are  highly  contorted. 
The  only  statement  I  can  find  as  to  the  mineralogical  nature  of  the 
substance  of  the  Pillar  is  that  of  Blatchley,  who  refers  to  it  as  made 
up  of  "satin  spar,  the  purest  form  of  carbonate  of  lime."  Having 
examined  somewhat  carefully  the  substance  of  several  hand  speci- 

*Indiana  Geol.  Survey,  1878,  p.  473. 
tO/.  cit.,  p.  156. 


254  Field  Columbian  Museum — Geology,  Vol.  i. 

mens  which  I  took  from  the  Pillar  I  find  them  to  be  made  up  chiefly 
of  aragonite.  Not  only  is  the  specific  gravity  that  of  aragonite  (2.92) 
as  obtained  by  Thoulet's  solution,  but  several  cavities  show  the  typi- 
cal radiating  bladed  crystals  of  this  form  of  carbonate  of  lime.  The 
occurrence,  therefore,  furnishes  an  exception  to  the  rule  noted  by 
Merrill*  that  the  onyx  marbles  are  generally  calcite.  Between  the 
distinctly  fibrous  layers  of  some  portions  are  interposed  other  layers 
microgranular  and  non-fibrous  in  structure.  The  substance  of  these 
I  found  to  be  of  lower  specific  gravity  than  that  of  the  fibrous  layers. 
It  is  in  other  words,  calcite.  Here,  then,  are  variations  from  arago- 
nite to  calcite  taking  place  in  the  growth  of  a  single  mass  represent- 
ing corresponding  variations  in  the  circumstances  of  its  growth.  A 
similar  occurrence  is  noted  by  Senftf  in  a  deposit  near  Eisenach, 
Germany.  It  is  unfortunate  that  our  present  knowledge  of  the  con- 
ditions bringing  about  the  formation  of  these  two  salts  is  so  inade- 
quate that  we  cannot  know  exactly  what  changes  are  indicated  by 
such  alternations. 

Age  of  the  Pillar. — The  immensity  of  this  stalagmite,  and  the 
certainty  that  it  has  been  formed  by  a  fairly  uniform  process  of 
deposition,  lead  almost  irresistibly  to  an  inquiry  as  to  whether  any 
satisfactory  estimate  of  the  length  of  time  required  for  the  forma- 
tion of  the  mass  can  be  made.  Some  attempts  seem  to  have 
been  made  to  determine  the  rate  of  deposition  by  measuring  the 
thickness  of  the  film  formed  upon  glass  vessels  left  in  the  water 
now  dripping  at  the  Pillar.  Unfortunately  these  measurements 
are  not  very  accurate.  Collett  states  on  ^ne  page  of  his  report 
(p.  467)  that  water  dripping  "at  the  '  Pillar  of  the  Constitution  '  has 
deposited  a  film  of  less  than  one-fiftieth  of  an  inch  during  five  years, 
or  at  the  rate  of  one  inch  in  250  years,"  while  on  another  page  (p. 
474)  he  states  that  "  an  estimate  based  on  quasi  observations  places 
the  rate  of  this  stalagmitic  growth  at  one  inch  in  100  to  150  years." 
Hovey,  in  his  "Celebrated  American  Caverns"  (p.  138),  speaks  of 
the  Pillar  as  growing  ten  inches  in  1,000  years,  though  he  gives  no 
data  on  which  to  base  the  statement.  Mr.  Rothrock,  the  present 
proprietor  of  the  cave,  has  at  my  request  had  a  new  vessel  placed 
in  the  water  since  my  visit  and  it  is  hoped  that  this  may  fur- 
nish a  means  of  accurate  measurement  in  a  few  years.  For  the 
present,  however,  taking  Collett's  lower  rate  of  one  inch  in  250  years 


*The  Onyx  Marbles:    their  origin,  composition,  etc.,  Rep.  U.  S.  Nat.  Mus.,  1893,  p.  553. 
tO/.  cit.,  p.  289. 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  255 

as  probably  the  nearest  correct,  it  can  be  easily  calculated  that  90,000 
years  would  have  been  required  for  the  Pillar  to  rise  to  its  present 
height  had  the  flow  of  water  during  all  this  time  been  uniform  over 
the  constantly  increasing  surface.  I  believe  it  safe  to  regard  this  as 
a  minimum  age  for  the  Pillar,  though  I  am  well  aware  that  owing  to 
various  factors  which  may  give  rise  to  fluctuations  of  growth,  geolo- 
gists are  accustomed  to  believe  that  no  satisfactory  time  values  can 
be  assigned  to  measurements  of  stalagmitic  deposits.  See  Dana's 
Manual  of  Geology,  4th  edition,  p.  1024.  But  may  not  these  fluctu- 
ations be  confined  within  limits  as  narrow  as  those  affecting  other 
measurements  of  time,  such  as  the  rate  of  recession  of  gorges  or  the 
rate  of  sedimentation,  especially  when  we  remember  that  variations 
in  the  rate  of  deposit  almost  certainly  find  expression  in  the  form  of 
the  stalagmite?  The  stalagmite  under  discussion  certainly  has  a 
remarkably  symmetrical  form.  I  believe,  therefore,  that  it  must  have 
grown  at  a  fairly  uniform  rate. 

Regarding  the  possibilities  of  arriving  at  any  satisfactory  value 
of  the  mean  age  of  the  Pillar,  I  have  no  very  lively  hope  of  suc- 
cess. It  is  hardly  likely  that  the  flow  of  calcareous  waters  over 
the  entire  mass  of  the  Pillar  was  constant  throughout  the  period  of 
its  growth.  At  the  present  time,  growth  is  hardly  taking  place  over 
one  one-hundredth  part  of  the  surface,  yet  a  mean  value  can  be 
assigned  to  this  factor  only  in  a  purely  arbitrary  way  with  nothing  to 
guide  the  judgment  that  I  can  think  of.  The  data  for  assigning  an 
age  value  to  the  large  stalagmite  now  in  the  Museum  of  Science  and 
Art,  Edinburgh,  seem  to  me  better  founded.  This  stalagmite  is  n 
feet  long  and  28  inches  in  diameter.  It  was  sawed  from  its  base  in  a 
cave  in  Bermuda  in  1819.  In  1863,  Sir  Alexander  Milne  in  visiting 
the  cave  measured  the  amount  of  matter  formed  on  the  base  since  the 
removal  of  the  stalagmite  and  found  it  to  be  five  cubic  inches.  At  that 
rate  it  can  be  easily  calculated  that  about  600,000  years  were 
required  for  the  formation  of  the  stalagmite.*  Numerous  considera- 
tions show  that  it  would  be  incorrect  to  apply  this  ratio  to  the  forma- 
tion of.  the  20,000,000  cubic  inches  of  matter  which  make  up  the 
Pillar  of  the  Constitution,  and  I  introduce  the  illustration  only  to 
show  that  a  much  greater  age  should  probably  be  assigned  the 
Pillar  than  that  which  I  have  given  as  a  minimum.  In  addition 
to  the  time  consumed  in  the  growth  of  the  Pillar,  a  large  previous 
period  was  required  for  the  erosion  of  the  chamber  in  which  it  stands. 


•My  data  are  from  the  Museum  label.    I  think  the  facts  have  been  published,  but  I  cannot 
give  the  reference. 


256  Field  Columbian  Museum — Geology,  Vol.  1. 

Data  are  meagre  for  estimating  the  length  of  this  period.  Prestwich* 
has  estimated  the  rate  of  erosion  by  the  Thames  as  one  inch  in  1,000 
years.  The  chalky  Cretaceous  and  Oolitic  strata  over  which  the 
Thames  flows  are  doubtless  eroded  at  a  more  rapid  rate  than  the  com- 
pact limestone  in  which  Wyandotte  cave  is  situated.  Taking  this 
rate,  however,  as  a  minimum,  it  will  be  found  that  a  period  of  360,000 
years  would  be  required  to  erode  the  "Senate  Chamber"  to  the 
depth  of  the  base  of  the  stalagmite. 


MARENGO   CAVE. 


The  Cave  Floor  Terrace. — The  greater  portion  of  the  floor 
of  this  main  cave  shows  a  well  marked  terrace  recording  two  distinct 
stages  in  the  life  of  the  stream  which  before  its  final  disappearance 
flowed  through  the  cave.  Of  these  two  stages  the  stream  of  the 
older  stage  had  a  width  of  from  15  to  20  feet  and  a  current  of 
sufficient  velocity  to  make  large  ripple  marks  on  its  bed  of  coarse 
alluvium.  These  ripple  marks  are  symmetrical  and  their  long 
slope  is  plainly  away  from  the  present  entrance  to  the  cave.  This, 
therefore,  was  the  direction  of  flow  of  the  stream.  In  its  second 
stage  the  stream  was  reduced  to  a  width  of  about  10  feet  and  its  cur- 
rent was  more  sluggish.  It  cut  a  trench  of  the  above  width  with 
nearly  vertical  walls  to  a  depth  of  about  two  feet  in  the  bed  of  the  old 
stream,  but  did  not  have  a  current  of  sufficient  velocity  to  produce 
ripple  marks  on  its  bed.  A  further  greater  sluggishness  as  compared 
with  the  first  stream  is  indicated  by  the  somewhat  winding  course 
which  it  took  through  the  bed  of  the  latter.  The  disappearance  of 
this  stream  must  have  taken  place  somewhat  suddenly,  for  there  has 
been  no  trenching  of  its  bed  nor  sloping  of  its  banks  such  as  would 
have  occurred  if  the  flow  of  water  had  diminished  gradually.  The 
bed,  now  quite  dry,  has  a  slightly  concave  form.  A  draining  away  of 
the  stream  by  the  opening  of  new  conduits  at  a  lower  level  seems  the 
most  natural  explanation  of  its  two  stages  and  final  disappearance. 
It  is  of  course  not  impossible  that  these  stages  mark  a  diminution  in 
rainfall  or  supply  of  waters  from  above,  but  there  is  on  the  whole 
little  reason  to  suspect  such  abrupt  changes  in  these  conditions.  It 
is  not  unlikely  that  the  large  spring  situated  a  few  rods  west  of  the 
present  entrance  represents  the  present  point  of  issue  of  the  stream. 


*Geology,  vol.  i,  p.  107. 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  257 

Stream  Deposit. — Gradual  diminution  in  rate  of  flow  is  well 
shown  in  the  deposit  left  by  a  stream  tributary  to  the  main  stream  to 
be  seen  at  the  point  called  the  "Sand  Pit"  between  the  "  Rock  of 
Gibraltar"  and  "Fortress  Monroe."  The  stream  had  a  course 
nearly  at  right  angles  to  that  flowing  through  the  main  cave,  although 
its  course,  as  its  channel  is  filled  nearly  to  the  roof,  can  not  be  fol- 
lowed backward  except  by  digging.  Where  this  tributary  emptied 
into  the  main  stream  it  formed  a  delta  deposit  about  eight  feet  in 
depth.  The  main  stream  in  cutting  downward  has  cut  through  this 
delta  so  as  to  expose  a  complete  section.  The  deposit  is  well  strati- 
fied. There  are  slight  variations  in  the  coarseness  of  adjacent  strata 
throughout  the  deposit,  but  the  most  striking  feature  is  the  obvious 
gradation  from  coarse  pebbles  at  the  bottom  to  fine  alluvium  at  the 
top.  The  pebbles  at  the  bottom  are  well  rounded  sandstone  pebbles 
having  about  the  size  of  English  walnuts.  Only  a  stream  of  con- 
siderable swiftness  and  volume  could  have  transported  them.  From 
such  a  velocity  of  current  the  stream  diminished  until  it  bore  only  the 
finest  alluvium  in  its  latest  stages.  What  could  have  led  to  such  a 
diminution  in  its  rate  of  flow  is  not  apparent,  but  it  is  evident  that 
waters  flowing  through  limestone  are  liable  at  any  time  and  to  any 
extent  to  be  drawn  off  in  new  directions  by  the  opening  of  new  con- 
duits. 

Abundance  of  Stalagmites. — A  remarkable  feature  of  the  por- 
tions of  the  cave  known  as  "Cave  Hill  Cemetery"  and  the  "Prison 
Cell"  is  the  relative  abundance  of  stalagmites.  Many  of  the  stalag- 
mites have  no  corresponding  stalactites  at  all.  There  can  be  little 
doubt  that  the  principles  enunciated  by  Senft*  provide  adequate  ex- 
planation of  the  origin  of  such  results.  Senft  showed  that  when 
the  flow  of  water  through  a  crevice  was  too  rapid,  either  on  account 
of  the  verticality  of  the  crevice  or  the  abundance  of  the  water  supply, 
to  allow  of  evaporation  and  consequent  deposition  sufficient  to  form 
a  stalactite,  a  stalagmite  might  yet  be  built  up  because  of  the  greater 
opportunity  for  evaporation  given  for  water  falling  upon  the  cave 
floor.  He  supported  this  conclusion  by  calling  attention  to  the  fact 
that  stalagmitic  icicles  form  during  the  hours  of  the  day  when  melting 
is  most  speedy.  These  suggestions  seem  to  furnish  sufficient 
explanation  for  the  facts  referred  to. 

Origin  of  Peculiar  Forms  of  Stalagmites. — The  form  of  many  of 
the  stalagmites  is  remarkable  and,  so  far  as' I  know,  peculiar  to  this 

Op.  cit.,  p.  287. 


•V 


258  Field  Columbian  Museum — Geology,  Vol.  i. 

cave.  The  form  to  which  I  refer  is  that  of  which  the  stalagmite 
known  as  "Washington's  Monument"  (Fig.  4)  may  serve  as  a  type. 
It  may  be  described  as  one  which  would   be   produced   by  piling   a 


- " !,  ^yi 

^H 

"^^fc 

;  -3 

*  T^B^?x 

■ .  >: .  y4 

v.- 

He  '  fej 

1 

■■ 

_  1  7J 

Fig.  4 — "Washington's  Monument,"  Marengo  Cave. 

number  of  irregular,  successively  smaller,  truncated,  inverted  cones 
one  above  the  other.  At  first'sight  this  structure  appears  very  regu- 
lar and  suggests  rhythmic  variations  in  the  supply  of  matter  in  the 
formation  of  the  stalagmite.  On  close  examination,  however,  it  will 
be  seen  that  the  widenings  and  narrowings  are  not  horizontal,  nor  do 
they  extend  uniformly  around.  They  are  rather  of  the  nature  of 
irregular  projections  and  indentations.  Such  being  the  case,  it 
seems  to  me  that  slight  movements  of  the  point  of  dropping  of  the 
water  which  formed  the  stalagmite  would  be  sufficient  cause  for  its 
form.  Such  variations  in  direction  of  growth  of  a  stalagmite  are 
illustrated  in  a  section  of  one  from  Robertson's  Cave,  Springfield, 
Missouri,  shown  in  Fig.  1,  PI.  XXXII.  Up  to  a  point  about  one-third 
of  the  way  to  the  top,  growth  was  in  a  direction  to  the  right.  Then 
it  turned  to  the  left  and  then  became  more  nearly  vertical.  Such 
variations  might  especially  be  expected  where  no  stalactite  existed 
above  to  maintain  the  point  of  dropping  in  one  place,  as  is  the  case 


LIBRARY 
UNIVERSITY  OP  ILLINOIS 

I »  D  R 


Explanation  of  Pl.  XXXII. 


Fig.  i.     Section    of    stalagmite    from 
Robertson  Cave,  Missouri, 
showing  changes  in  direc- 
tion of  growth. 
(Mus.  No.  G  604.) 


Fig.  2.     Cone-shaped    stalagmite, 
Marengo  Cave. 
(Mus.  No.  G   1022,) 


Feb.  igoi.     Observations  on  Indiana  Caves— Farrington.  259 

with  those  under  discussion.  If  it  be  considered  further  that  varia- 
tions in  the  form  of  a  stalagmite  may  result  from  variations  in  the 
rate  of  evaporation  and  content  of  carbonate  of  lime  of  the  water 
which  produces  it,  further  reasons  for  the  peculiarity  of  form  will  be 
added.  Thus,  if  evaporation  is  rapid,  or  the  content  of  carbonate  of 
lime  high,  so  that  a  large  quantity  of  the  salt  contained  in  each  drop 
is  deposited  at  the  top  of  the  stalagmite  and  little  is  left  to  be 
relinquished  in  the  subsequent  course  of  the  water  down  the  sides,  a 
long,  slender  stalagmite  will  be  formed.  If,  on  the  other  hand, 
evaporation  is  slow,  or  the  content  of  carbonate  of  lime  low,  so  that 
deposition  will  take  place  about  equally  during  the  course  of  the 
water  over  the  stalagmite,  a  broadly  conical  stalagmite  will  result. 
It  is  evident  that  such  variations  occurring  during  the  growth  of  any 
single  stalagmite  would  find  expression  in  corresponding  forms  in 
different  parts  of  the  stalagmite. 

Another  form  of  stalagmite  so  far  as  I  know  peculiar  to  this  cave 
is  that  of  a  flattened  cone.  Such  are  the  stalagmites  known  as  "  Mt. 
Vesuvius"  and  the  "Diamond  Dome."  The  form  is  illustrated  by 
Fig.  2,  PI.  XXXII,  showing  a  stalagmite  collected  by  the  writer  at  the 
cave.  I  have  indicated  above  in  what  manner  slight  evaporation  as 
compared  with  the  rate  of  flow  of  water  or  a  relatively  low  content  of 
carbonate  of  lime  might  be  expected  to  produce  such  a  form.  It  may 
be  further  noted  that  the  lateral  surface  of  these  stalagmites,  instead 
of  being  smooth  like  that  of  the  ordinary  stalagmite,  is  built  out  in  a 
series  of  sinuous  walls  running  more  or  less  horizontally  around  the 
cone.  These  walls  form  numbers  of  little  pools  usually  filled  with 
water  and  containing  delicate  crystalline  aggregations  of  carbonate  of 
lime.  The  low  slope  of  the  surface  allowing  slow  movement  of  the 
water  over  it  is  doubtless  responsible  for  the  construction  of  these 
walls. 

Stalagmo-Stalactite8. — Usually  in  the  growth  of  cave  formations, 
a  stalactite  forms  above  its  counter  stalagmite.  An  odd  reversal  of 
this  condition  of  things  so  that  the  stalagmite  forms  above  the  stalac- 
tite is  to  be  seen  in  several  instances  in  this  cave,  the  formation 
known  as  the  "  Mermaid  "  being  perhaps  the  best  example.  Such 
stalagmo-stalactites  are  formed  by  a  drip  taking  place  on  the  edge  of 
a  limestone  shelf  so  that  the  water  which  builds  up  the  stalagmite,  in 
pursuing  its  further  downward  course  forms  a  stalactite  as  well.  Of 
the  general  appearance  of  such  formations  Fig.  5,  showing  a  speci- 
men collected  in  Shiloh  Cave,  will  give  a  sufficient  idea. 


26o 


Field  Columbian  Museum — Geology,  Vol.  i. 


Molecular  Arrangement  of  Stalactites  and  Stalagmites.— The 
substance  composing  the  stalactites  and  stalagmites  of  this  cave  is 
generally  made  up  structurally  of  fibres  radiating  outward  from  the 

center.  The  fibres  pass  unin- 
terruptedly through  the  concen- 
tric rings  of  growth  and  the 
structure  is  doubtless,  therefore, 
as  pointed  out  by  Merrill,*  of 
secondary  origin.  The  fibrous 
substance  is  not,  however, 
aragonite,  but  calcite.  In  con- 
trast to  the  forms  possessing 
this  structure  are  many  whose 
substance  has  a  wholly  coarsely- 
crystalline  structure  exhibiting 
an  all-pervading  rhombohedral 
cleavage.  Intermediate  stages 
between  these  two  extremes  can 
be  seen  in  many  cases.  Of 
especial  interest  are  stalagmites 
exhibiting  a  structure  like  that 
shown  in  Fig.  6.  This  figure 
shows  a  cross  section  of  a 
stalagmite,  the  peripheral  por- 
tions of  which  are  fibrous  in 
structure  while  the   central  are 

Fig.  5— Stalagmo-Stalactite,  Shiloh  Cave.  ,  ,     .       ,      ,  T  r       , 

(Mus.  No.  G.  884.)  rhombohedral.       I    am    of    the 

opinion,  though  I  know  of  no  way  either  of  proving  or  disproving 
it,  that  such  a  structure  is  evidence  of  a  progressive  change  in  the 
molecular  arrangement  of  the  substance  toward  a  more  stable  con- 
dition. It  is  certain  that  it  is  in  the  older  portion  of  the  stalagmite 
that  the  molecules,  are  arranged  along  the  rhombohedral  planes,  and 
I  have  never  found  the  positions  reversed.  That  the  rhombohedral 
condition  is  more  stable  than  the  fibrous  seems  to  be  indicated  by 
the  fact  that  the  former  is  characteristic  of  the  oldest  and  most  meta- 
morphosed calcite-bearing  rocks.  Prof.  D.  G.  Elliot  has  suggested 
to  me  that  pressure  on  the  internal  substance  of  the  stalagmite  may 
also  be  largely  instrumental  in  bringing  about  the;$feange  to  a  rhom- 
bohedral condition.  This  is  not  unlikely.  But  whatever  the  deter- 
mining causes,  the  case  seems  to  furnish  an  instructive  illustration  of 


*Op.  cit.,x>.  78. 


Feb.  igoi.     Observations  on  Indiana  Caves — Farrington.  261 

progressive  molecular  arrangement.  The  carbonate  of  lime  was 
deposited  first  in  narrow,  concentric  bands.  The  substance  then 
rearranged  itself  in  the  form  of  more  or  less  continuous  fibres 
arranged  at  right  angles  to  the  planes  of  deposition.  Then  with  the 
lapse  of  time  and  pressure  a  second  rearrangement  was  made  by 
which  the  attractive  forces  brought  the  molecules  together  grouped 
along  rhombohedral  planes. 


Fig.  6 — Broken  end  of  stalagmite,  showing  change  from  fibrous  to  rhombohedral  structure. 

Rate  of  Growth  of  Stagmalites. — I  propose  this  word,  com- 
pounded from  drdy/ua  (drop)  and  MOos  (stone),  as  a  general  name  for 
formations  produced  by  dropping  water. 

Under  the  present  usage  the  expression  stalactites  and  stalag- 
mites, each  term  of  which  has  a  limited  meaning,  is  the  only  one 
available.  So  many  stagmalites  in  this  cave  are  in  process  of  forma- 
tion that  it  seems  a  favorable  place  for  a  study  of  their  rate  of  growth 
and  of  the  variations  which  occur  in  this  rate.     In  the  hope  of  obtain- 


262  Field  Columbian  Museum — Geology,  Vol.   i. 

ing,  in  the  lapse  of  years,  some  data  on  this  point  Mr.  S.  M.  Stewart, 
manager  of  the  cave,  kindly  allowed,  at  my  request,  several  stalac- 
tites and  one  stalagmite  to  be  marked  by  Mr.  Claude  Stroud,  who 
lives  near  the  cave,  and  who,  by  keeping  watch  of  their  growth,  can 
note  any  variations  which  they  undergo.  It  will  be  understood,  how- 
ever, that  the  rate  of  growth  is  so  slow  that  it  is  not  likely  that  before 
the  end  of  ten  years  at  least  any  appreciable  change  will  have  taken 
place.     The  record  of  the  stalactites  marked  is  as  follows: 

No.  1  Near  "  Tower  of  Babel,"  Drops  at  intervals  of  3V2  minutes. 
No.  2  In  "Queen's  Palace,"  "        "  "        "  45  seconds. 

No.  3    "  "  "  il      216  times  per  minute. 

These  are  simple  stalactite  tubes. 

The    stalagmite    marked    is   in   "Crystal    Palace  Gallery,"   and 
receives  eighteen  drops  a  minute. 


SH1LOH  CAVE. 


Eroded  Stalactites. — The  stalactite  shown  in  Fig.  7,  occurring 
near  the  southern  end  of  the  cave,  furnishes  an  interesting  illustra- 
tion of  the  fact  that  cave  waters  may  vary  in  their  action  from  forma- 
tive to  erosive,  according  to  the  quantity  of  carbonate  of  lime  they 
contain.  Thus,  in  the  case  of  the  stalactite  here  represented,  the 
waters  flowing  over  the  limestone  shelf  to  which  it  is  attached  had  at 
one  time  built  it  up  to  the  general  form  shown.  Later,  however, 
the  character  of  the  waters  changed  and  they  began  to  erode,  as  shown 
by  the  pits  on  the  surface,  the  very  mass  they  had  previously  built 
up.  These  processes  of  deposition  and  erosion  are,  of  course,  going 
on  side  by  side  in  nearly  all  limestone  caves,  but  it  is  not  often  that 
erosion  follows  so  rapidly  after  deposition.  Many  smaller  stalactites 
in  other  parts  of  the  cave  show  similar  erosion. 

Leaf  Stalactites. — Many  of  the  stalactites  of  this  cave  are  leaf- 
like in  their  form  so  far  as  this  may  describe  a  broad,  thin  and 
pointed  shape.  Often  the  appearance  is  that  of  a  series  of  ovate 
leaves  folded  along  their  midribs  and  hanging  down  from  a  project- 
ing ledge.  The  "leaves"  of  one  such  projecting  mass  are  nearly 
six  feet  in  length,  and  the  weight  of  the  mass  must  be  several  thou- 
sand pounds.      It  is  remarkable  that  such  a  weight  can   be  sustained 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.  263 


Fig. 


as  it  is  at  right  angles  to 
the  wall.  Observation 
of  the  broken  end  of 
any  of  the  "leaves"  of 
such  a  group  of  stalac- 
tites will  show  the  man- 
ner of  growth.  (See 
Fig.  8.)  Such  growths 
are  not  formed  by  water 
trickling  down  a  crevice, 
but  from  currents  de- 
bouching over  a  lime- 
stone sheff.  The  shelf 
must  project  slightly 
and  the  current  of  water 
must  be  relatively  large. 
There  are  first  formed 
stalactites  of  the  ordi- 
nary conical  type.  Then 
deposition  is  confined 
only  to  one  side  of  the 
stalactite,  the  side, 
namely,  over  which  the 
descending  water  flows. 
Growth  takes  place  then 
almost  wholly  in  this 
A  deposit  is,  however,  also 


-Eroded  Stalactite.  Shiloh  Cave. 
(Mus.  No.  G.881). 

direction  and  in  the  direction  of  length 
built  up  from  the  surface  of  the  shelf  by  the  water  flowing  over  it. 
So  the  mass  grows  upward  in  a  thin  layer,  downward  at  the 
stalactite  points  and  outward  in  thin  sheets  at  right  angles  to  the 
cave  wall.  There  is  also  a  slight  lateral  growth  of  the  stalactites 
which  causes  them  in  time  to  join  one  another,  and  the  group  thus 
acquires  the  appearance  of  a  continuous  sheet  thrown  into  folds. 
The  original  stalactite  points  usually  continue  to  be  the  points  of 
greatest  growth  in  length,  but  the  stalactite  may  be  longest  some 
distance  away  from  these.  Corrugations  of  the  surface  showing 
retardations  of  the  flowing  waters,  and  similar  to  those  so  common 
on  icicles,  are  nearly  always  present.  If  the  current  is  compara- 
tively narrow  and  maintains  its  position  for  a  long  period  of  time  the 
stalactitic  mass  will  take  a  semi-circular  form  owing  to  the  fact  that 
the  portions  in  the  center  of  the  current  receive  more  material  than 


264 


Field  Columbian  Museum — Geology,  Vol.  i. 


those  at  the  side.  The  mass  in  Shiloh  Cave  mentioned  above  and 
the  "Canopy"*  in  Wyandotte  Cave,  are  excellent  illustrations  of 
such  formations. 


COAN'S  CAVE. 


The  spelling,  "Coon's",  given  by  Blatchiey|  for  the  name  of  this 
cave  seems  to  be  incorrect.  According  to  residents  of  the  region  the 
cave  derives  its  name  from  one  of  the  original  owners  of  the  land  on 
which  the  cave  is  situated,  whose  name  was  Coan. 

The  entrance  to  the  cave  is  well-shaped,   and  is  not  unlike  the 

« m; 


Fig.  8— Diagram  illustrating  manner  and  directions  of  growth  of  leaf  stalactites.    The  arrow  shows 
the  direction  of  the  water  current.    The  cross  section  at  the  left  shows  rings  of  growth. 

descriptions  given  of  cenotes  previously  referred  to.  The  cavity 
gradually  enlarges  toward  the  bottom.  A  small  surface  stream  occa- 
sionally flows  into  the  cave.  The  entrance  is  a  good  illustration  of 
ingress  obtained  by  following  the  path  of  the  stream  which  has 
formed  the  cave,  in  contrast  to  the  entrance  to  Wyandotte  and  Mam- 
moth Caves,  which  are  of  the  nature  of  openings  made  by  a  fallen 
roof. 


♦Figured  in  Report  of  Indiana  Geological  Survey  for  1896,  PI.  X. 
tO/.  cil.,  p.  129. 


LIBRARY 
UNIVERSITY  OF  ILLINOIS 

URSANA 


FIELD  COLUMBIAN    MUSEUM. 


GEOLOGY,    PL.XXXIII. 


Explanation  of  Pl   XXXIII. 


Strings  of  crystals  obtained  from  solutions  of  copper  sulphate,  lead  chlnrkh 
and  nickel-alum,  showing  increase  in  size  of  crystals  and  amount  of  deposit 
toward  the  bottom  of  the  solutions.  A  shot  used  to  weight  the  string  appears  in 
the  central  figure. 


Feb.  1901.     Observations  on  Indiana  Caves — Farrington.         265 


m 


m 


The  most  unique  feature  of  this  cave  is  the  pool  at  its  end, 
excellently  described  by  Blatchley.* 

The  calcite  crystals  which  line  the  walls  of  the  pool  are  made  up 
of  the  unit  rhombohedron  r  (1011)  and  the  unit  prism  of  the  first 
order  m  (1010).  (Fig.  9.)  The  crystals  have  all  grown  in  a  direction 
at  right  angles  to  the  plane  of  their  attachment.  The  prism  is  quite 
short,  and  no  crystals  are  doubly  terminated.  The  crystals  vary  in 
size  from  quite  minute  to  those  the  size  of  an  ordinary  acorn.  It  is 
noticeable  that  they  increase  in  size  toward  the  bottom  of  the  pool. 

In  order  to  determine  whether  it  was 
commonly  true  that  crystals  increased 
in  size  toward  the  bottom  of  a  solution, 
with  the  assistance  of  Mr.  H.  W. 
Nichols,  I  prepared  solutions  of  a 
number  of  salts,  placed  them  in  long 
slender  jars  and  then  immersing  strings 
vertically,  noted  the  quantity  and  size  of 
crystals  deposited.  In  nearly  every 
case  the  deposit  took  a  marked  conical 
form.  The  base  of  the  cone  and  there- 
fore the  greatest  amount  of  deposit  was 
at  the  lowest  point  in  the  solution.  It 
was  also  generally  true  that  the  size  of 
the  crystals  increased  toward  the  bottom.  The  accompanying  plate 
(PI.  XXXIII),  showing  strings  of  crystals  obtained  from  solutions  of 
copper  sulphate,  lead  chloride  and  nickel-alum,  illustrates  this.  Such 
results  point  to  a  greater  concentration  of  solutions  at  the  bottom, 
a  principle  already  established  with  regard  to  solutions  in  general  by 
Ludwig  and  Soret.f  It  may  be  worth  while,  however,  to  call  atten- 
tion to  this  illustration  of  the  principle,  and  to  the  fact  that  the 
size  of  crystals  depends  on  the  degree  of  concentration  of  the  solution 
no  less  than  on  the  time  given  for  their  formation. 

In  this  part  of  the  cave  stalactites  and  stalagmites  of  the  ordi- 
nary type  appear  in  close  association  with  the  crystal  deposits  just 
described.  The  formations  have  a  similar  origin  in  that  they  are 
both  deposits  of  carbonate  of  lime  from  solution  in  water.  They 
differ  only  in  the  condition  that  in  the  making  of  stalactites  and  stal- 
agmites the  water  was  moving,  while  in  the  making  of  crystals  it  was 
still.     If  I  am  correct  in  this  conclusion  the  converse  of  the  principle 


Fk;.  9— Calcite,  Coan's  Cave. 


*Op.  cit..  p.  132. 

tBecker,  Am.  Jour.  Sci.,  Vol.  153,  pp.  21-40. 


266  Field  Columbian  Museum — Geology,  Vol.  i. 

affords  a  rule  perhaps  of  some  value  as  a  guide  to  the  conditions 
under  which  banded  formations  have  taken  place  as  compared  with 
those  which  exhibit  distinct  crystals.  Substances  deposited  from 
solution  in  water  which  exhibit  a  banded  or  layered  structure  have, 
according  to  this  rule,  been  formed  by  moving  waters,  while  those  in 
the  form  of  distinct  crystals  have  been  deposited  from  waters  at  rest. 
Hence,  the  banded  structure  so  characteristic  of  mineral  veins  may 
be  considered  proof  that  the  deposit  was  formed  from  moving  waters 
while  the  occasional  cavities  lined  with  crystals  show  points  at  which 
the  solutions  were  at  rest.  Similar  conclusions  may  be  drawn 
regarding  the  same  structures  as  seen  in  agates  and  geodes.  It  is 
evident,  further,  that  the  conditions  in  the  two  cases  also  differ 
in  the  quantity  of  liquid  present  and  in  the  rate  of  deposition.  The 
layered  structure  is  the  result  of  trickling  waters  from  which  deposi- 
tion is  necessarily  rapid,  while  the  distinct  crystals  were  formed  from 
a  solution  which  was  present  in  quantity,  and  from  which  deposition 
was  comparatively  slow.  The  applications  of  these  principles  to 
conclusions  regarding  the  origin  of  veins  are  obvious.  The  terms 
motion  and  rest  are,  of  course,  here  to  be  understood  in  a  purely 
relative  sense,  as  no  body  of  liquid  would  be  entirely  free  from 
internal  currents.  Further,  it  is  to  be  granted  that  all  gradations 
may  be  traced  between  a  banded  structure  and  distinct  crystals.  In 
a  broad  sense,  however,  the  rule  stated  in  these  terms  may  be  of 
some  value. 


